A program of laboratory and observational studies is proposed to examine the normal changes in parent-child interaction as a function of the child's developmental transition from middle childhood to adolescence. Although changes in parent-adolescent relations have been the subject of considerable formal and informal speculations, few empirical studies have been conducted to examine the nature and sources of these changes. A basic premise of the proposed research is that rapid cognitive, socioemotional, and physical changes in the transition to adolescence often result in distortions of interpersonal perceptions and attributions by both adolescents and parents that in turn may lead to conflict, dysfunctional or ineffective responses on both sides, and personal and interpersonal stress. The initial phases of this long-term research program consist of studies of social-cognitive and interpersonal processes pertinent to an understanding of stress in normal parent-adolescent interactions, including: (1) adults' expectations and behavioral and emotional responses to age-related changes in adolescents; (2) adolescents' concepts of and attributions regarding parental behavior and parent-child interactions; and (3) perceptions by adolescents and their parents of interactions they consider characteristic of themselves. Parents of adolescents and other adults age 25-40 and preadolescents age 9-16 will participate. Social-structural variables (e.g., social class, number of parents in the home, age of parents) will be restricted by the sampling methods in the first phase of the research in order to focus on basic psychological and interpersonal processes, but will be examined in subsequent work. Methods will include laboratory experiments, questionnaires and interviews, and observations of family interactions in homes and in laboratories. A hallmark of the approach is an oscillation between observational and experimental methods in order to clarify and test the cross-situational validity of findings. The results of these studies should provide a basis for identifying potential ways in which parents and mental health and other professionals may help adolescents and families cope adaptively with stresses that occur during the transition into adolescence.